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<h1>Surface. </h1>

<p>There are four main types of courts depending on the materials used for the court surface: clay courts, hard courts, grass courts and carpet courts. 
Each playing surface has its own characteristics which affect the playing style of the game.
Of the <gale:a href="grandslam">Grand Slam tournaments</gale:a>, the <gale:a href="us_open">US Open</gale:a> and <gale:a href="aus_open">Australian Open</gale:a> use hardcourts (though both used 
grass courts in the past, and the <gale:a href="us_open">US Open</gale:a> also used clay courts from 1975 through 1977), the <gale:a href="roland_garros">French Open</gale:a> 
is played on clay (though it too was played on grass before 1928), and <gale:a href="wimbledon">Wimbledon</gale:a> has always been played on grass.</p>

<h2>Clay courts</h2>
<p>Clay courts are made of crushed shale, stone, or brick. The red clay is slower than the green, Har-Tru, "North-American" clay. The <gale:a href="roland_garros">French Open</gale:a> uses clay courts, 
unlike the other three <gale:a href="grandslam">Grand Slam tournaments</gale:a> of each year.
Clay courts slow down the ball and produce a high bounce when compared to grass courts or hard courts. This is because clay courts have more grab 
and when the ball lands there is more friction pushing against the ball's horizontal path, therefore slowing it and creating a higher bounce. For this reason, the clay 
court takes away some advantage of big serves, which makes it hard for serve-based players to dominate on the surface. Clay courts are cheaper to construct than other 
types of tennis courts, but the maintenance costs of a clay surface are higher than those of hard courts. Clay courts need to be rolled to preserve flatness. The clay's 
water content must be balanced; green courts generally require the courts to be sloped[citation needed] to allow water run-off.
Clay courts are more common in Europe and Latin America than in North America and tend to heavily favor baseline players.</p>

<h2>Grass courts</h2>
<p>Grass courts are the fastest type of courts in common use (AstroTurf is faster but is primarily used only for personal courts). They consist of grass grown on very hard-packed soil, 
which adds an additional variable: bounces depend on how healthy the grass is, how recently it has been mown, and the wear and tear of recent play. Points are usually very quick where 
fast, low bounces keep rallies short, and the serve plays a more important role than on other surfaces. Grass courts tend to favour serve-and-volley tennis players, such as John McEnroe 
and Stefan Edberg among men and Martina Navratilova and Jana Novotna among women. The International Tennis Hall of Fame in Newport, R.I., comprises grass courts. The surface is less firm 
and more slippery than hard courts, causing the ball to slide and bounce lower, and so players must reach the ball faster. Serve-and-volley players take advantage of the surface by serving 
the ball (usually a slice serve because of its effectiveness on grass) and then running to the net to cut off the return of serve, leaving their opponent with little time to reach the 
low-bouncing, fast-moving ball. Players often hit flatter shots to increase power and allow the ball to travel faster before and after the ball hits the ground.</p>
<p>Grass courts were once among the most common tennis surfaces, but are now rare due to high maintenance costs, as they must be watered and mown often, and take a longer time to dry 
after rain than hard courts. For a more extensive discussion of the skills most advantageous on grass court, see grass-court specialist.</p>

<h2>Hard courts</h2>
<p>Hard courts are very fast types of tennis courts, where hard-hitting players have a slight advantage. Hard courts can vary in speed; they are faster than clay but not as fast as grass courts. 
Depending on the amount of sand added to the paint the amount the ball slows down can vary greatly. These courts are considered the most equal for all playing styles. The <gale:a href="us_open">US Open</gale:a> is played 
on an acrylic hard court, while the <gale:a href="aus_open">Australian Open</gale:a> is played on a synthetic hard court. The main difference between a synthetic hard court and a true hard court surface is the level of hardness. 
When the ball bounces on this surface it is faster than all other surfaces if there is not much sand in the top paint. The amount of sand used in the top paint and the size of the sand also determines 
the speed – more sand means less speed and larger sand particles will slow the speed of play. The amount of friction can also be altered and more friction will produce a clay court effect, where 
topspin is magnified. The extra grip and friction will resist the sliding effect of the ball and the resistance will force the ball to change its rotation. The extra grip provided by the surface 
can resist the movement of the player and can cause injury.</p>

<h2>Carpet courts</h2>
<p>Carpet is a tennis term for any removable court covering. A short form of artificial turf weighted with sand is common in Asia. Indoor arenas store rolls of rubber-backed court surfacing and 
install it temporarily for tennis events.</p>

<h2>Indoor courts</h2>
<p>Hard courts are most common indoors. Slower, higher bouncing rubberized surfaces are used for a cushioned feel. Clay courts are installed indoors with underground watering systems. Barnstorming 
professionals played on canvas laid over wooden basketball courts up to the 1960s.</p>


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